Gas valves for use with gas burners to provide thermocouple controlled safety operation and "supersafe" operation have been known for some time. Such gas valves have a thermocouple energized electromagnet for holding in a safety apparatus when the thermocouple is heated by the presence of a pilot flame; so that, a main safety valve cannot be opened until the pilot flame is proven. Additionally, such valves have "supersafe" apparatus to prevent the main safety valve from being reopened once the valve is closed by turning the main control knob to the off position. When the thermocouple has cooled to allow the electromagnet to be de-energized, the reset of the safety mechanism from an inital starting condition is possible; so that, a safe lighting operation of the pilot must always take place.
Gas valves with various types of thermocouple controlled safety apparatus and "supersafe" apparatus are shown in the following patents and applications: William R. Ray U.S. Pat. No. 3,303,866 which issued Feb. 14, 1967; Hollis L. Randolph U.S. Pat. No. 3,682,188 which issued Aug. 8, 1972; Otto Thomas U.S. Pat. No. 2,988,098 which issued June 13, 1961, Richard K. Fairley et al U.S Pat. No. 3,451,407 which issued June 24, 1969; Nico Van der Linden U.S. Pat. No. 3,572,355 which issued Mar. 23, 1971; Cornelis Kingma U.S. Pat. No. 3,476,130 which issued Nov. 4, 1969; and Paul Dietiker U.S. Pat. No. 3,877,475 which issued Apr. 15, 1975.
The present invention is concerned with a gas valve having a thermocouple controlled safety apparatus and a "supersafe" operation apparatus wherein a single tilting latch member is used on an operating shaft to provide both such operations; thereby, providing a gas valve which is simple and inexpensive to manufacture. The latch member is attached to the single operating shaft so that when the shaft is moved axially, a pilot valve is opened and the thermocouple connrolled safety apparatus is reset. If the resetting operation takes place, upon a partial return of the shaft in the opposite direction the pilot valve will remain open and the main gas valve will be opened. Upon a rotation and release of the main control knob, the pilot valve and main safety valve are turned off. The latch member prevents the resetting of the safety valve, even though the thermocouple controlled safety apparatus is still in the energized position with the thermocouple still being hot. The resetting operation cannot be accomplished to open the main safety valve until the thermocouple cools down thus providing the "supersafe" operation.